Marriage may be good for the heart in more ways than one. According to a new study, married adults who undergo heart surgery are three times more likely than single people to survive the three months immediately following their operation.

Marriage boosted survival in both men and women, the study found. “That’s a dramatic difference in survival rates for single people, during the most critical post-operative recovery period,” said Ellen Idler, a sociologist at Emory University and lead author of the study, in a statement.

In the study, researchers interviewed 500 patients before they underwent emergency or elective coronary bypass surgery. Then, they analyzed the patients’ responses with survival data from the National Death Index.

Sadly for singles, the study found that heart surgery survival rates were rather bleak compared with those of married patients. Indeed, the marriage benefit lasted beyond the initial three-month recovery period and continued for up to five years after surgery. Among patients who survived the initial three months, singletons were about 71% more likely to die during the next five years.

Although the data couldn’t conclusively determine why married people survived longer, the researchers say their patient interviews were revealing. “The married patients had a more positive outlook going into the surgery, compared with the single patients,” Idler said in the statement. “When asked whether they would be able to manage the pain and discomfort, or their worries about the surgery, those who had spouses were more likely to say, yes.”

But greater cheerfulness was not the only predictor of survival. Researchers also found that smoking rates differed greatly between singles and married people. Smoking history accounted for the lower five-year survival rate among singles, researchers said, and overall, married folks were less likely to smoke than their single peers. That suggests that spouses have something to do with our smoking habits, which in turn affects our long-term health.

Partners are also known to be good for reminding us day-to-day to take our prescribed medicine and to eat healthy. According to Richard Contrada, one of the study’s authors and a professor of psychology at Rutgers University, marriage may further benefit long-term survival because couples provide each other with social support in times of stress. “Marriage may promote health through companionship,” says Contrada. “This is not as well understood, but it could involve emotional benefits of being physically close, holding and touching, and by sharing mentally and behaviorally engaging activities.”

But if the latest data are any indication, Americans may be benefiting less and less from the bonds of matrimony. Barely half of U.S. adults are currently married — the lowest percentage ever — according to the Pew Research Center. Maybe it’s time to reconsider saying “I do.”

The study is published in the March issue of the Journal of Health and Social Behavior.